Generally, in processes of preparing materials in a liquid state such as polymer preparing processes, viscosities of intermediate products and viscosities of reactants in a reactor are important information for managing reaction conversion rates and product qualities.
Furthermore, viscosities of polymer solutions or suspensions, and the like vary depending on shear strain rates acting on fluids. However, since the conventionally used online viscometers can measure only viscosities of specific shear strain rates, they have a limit difficult to accurately measure rheological characteristics of fluids.